An Extrinsic Faradaic Layer on CuSn for High-Performance Electrocatalytic CO2 Reduction

An intrinsic Faradaic layer on the surface of a metal electrocatalyst is usually considered an active site for CO2 reduction. Different strategies have been used to improve the performance of CO2 reduction by adjusting the intrinsic Faradaic layer. However, it is still challenging to achieve CO2 reduction with high activity, selectivity, and stability. In this study, for the first time, we improve the three parameters simultaneously by introducing a Zn(OH)(x) over layer onto a CuSn electrocatalyst. We find that the intrinsic Faradaic layer of Sn(OH)(x) on the surface of CuSn provides active sites for CO2 reduction, while Zn(OH)(x) plays multiple roles as an adsorption/activation layer, a cover layer, and a protective layer. Further studies suggest that the enhanced activity comes from a Faradaic reaction of Zn(OH)(x) during CO2 reduction, which can be considered as an extrinsic Faradaic layer. This new strategy of introducing an extrinsic Faradaic layer can deepen understanding of electrocatalytic process and offers guidance to design other high-performance electrocatalysts. [GRAPHICS] .

Automated summary

This study improves the activity, selectivity, and stability of CO2 reduction by introducing a Zn(OH)(x) overlayer onto a CuSn electrocatalyst. The Sn(OH)(x) intrinsic Faradaic layer on the surface of CuSn provides active sites for CO2 reduction, while Zn(OH)(x) plays multiple roles.